For example, a liquid crystal panel used for a liquid crystal display device such as a liquid crystal television set does not emit light by itself, and therefore, requires a separate backlight unit as a lighting device. The backlight unit is installed on aback side of the liquid crystal panel (side opposite to a display surface) and includes a chassis, a surface of which is opened on the liquid crystal panel side, a light source stored in the chassis, and an optical member (diffuser sheet, etc.) that is arranged on the opening side of the chassis and efficiently discharges light emitted from the light source to the liquid crystal panel. Among the above-mentioned components of the backlight unit, the light source adopts, for example, an LED, and in such case, an LED board that mounts the LED thereon is stored in the chassis.
An example of the backlight unit using the LED as the light source is described in Patent Document 1.